[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.712049][ T26] audit: type=1800 audit(1572782717.286:25): pid=6979 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.738789][ T26] audit: type=1800 audit(1572782717.296:26): pid=6979 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.766220][ T26] audit: type=1800 audit(1572782717.296:27): pid=6979 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.100' (ECDSA) to the list of known hosts. 2019/11/03 12:05:29 fuzzer started 2019/11/03 12:05:30 dialing manager at 10.128.0.105:43165 2019/11/03 12:05:30 syscalls: 2554 2019/11/03 12:05:30 code coverage: enabled 2019/11/03 12:05:30 comparison tracing: enabled 2019/11/03 12:05:30 extra coverage: extra coverage is not supported by the kernel 2019/11/03 12:05:30 setuid sandbox: enabled 2019/11/03 12:05:30 namespace sandbox: enabled 2019/11/03 12:05:30 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/03 12:05:30 fault injection: enabled 2019/11/03 12:05:30 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/03 12:05:30 net packet injection: enabled 2019/11/03 12:05:30 net device setup: enabled 2019/11/03 12:05:30 concurrency sanitizer: enabled syzkaller login: [ 51.024443][ T7144] KCSAN: could not find function: 'poll_schedule_timeout' 2019/11/03 12:05:49 adding functions to KCSAN blacklist: 'wbt_issue' 'kvm_arch_vcpu_load' 'ktime_get_real_seconds' 'xas_find_marked' 'blk_mq_get_request' 'pcpu_alloc' 'n_tty_receive_buf_common' 'find_match' 'kauditd_thread' 'poll_schedule_timeout' '__writeback_single_inode' '__hrtimer_run_queues' 'tcp_poll' 'find_next_bit' 'mod_timer' 'do_syslog' 'pipe_wait' 'ksys_read' 'generic_file_read_iter' 'd_alloc_parallel' 'tick_sched_do_timer' 'blk_mq_sched_dispatch_requests' 'page_counter_try_charge' '__nf_conntrack_find_get' 'update_defense_level' 'install_new_memslots' 'virtqueue_disable_cb' 'rcu_gp_fqs_loop' 'snd_seq_check_queue' 'generic_write_end' '__dentry_kill' 'p9_poll_workfn' 'shmem_file_read_iter' 'ext4_free_inode' '__snd_rawmidi_transmit_ack' 'ext4_nonda_switch' 'bio_chain' 'fsnotify' '__dev_queue_xmit' 'tomoyo_supervisor' 'taskstats_exit' 'mem_cgroup_select_victim_node' 'getboottime64' 'pfkey_recvmsg' '__remove_hrtimer' 'ep_poll' '__splice_from_pipe' 'sit_tunnel_xmit' 'copy_process' 'virtqueue_enable_cb_delayed' 'inode_permission' 'tcp_add_backlog' 'pipe_poll' 'blk_mq_dispatch_rq_list' 'skb_dequeue' '__fput' 'generic_permission' 'pid_update_inode' 'ktime_get_seconds' 'echo_char' 'add_timer' 'rcu_gp_fqs_check_wake' 'ext4_mb_good_group' 'ext4_free_inodes_count' '__ext4_new_inode' 'tick_do_update_jiffies64' 'tomoyo_check_acl' 'evict' 'blk_mq_run_hw_queue' 'dd_has_work' 'inet_putpeer' 'do_signal_stop' '__tcp_select_window' 'run_timer_softirq' '__nf_ct_refresh_acct' 'ext4_has_free_clusters' 'tick_nohz_idle_stop_tick' 'audit_log_start' 'do_exit' 'task_dump_owner' 'vm_area_dup' 'generic_fillattr' 'find_get_pages_range_tag' 'timer_clear_idle' 'do_readlinkat' 'mm_update_next_owner' 'ext4_mark_iloc_dirty' 'ip_finish_output2' 'do_nanosleep' 'snapshot_refaults' 'fat16_ent_put' [ 236.873574][ T7142] ================================================================== [ 236.881700][ T7142] BUG: KCSAN: data-race in handle_mm_fault / watchdog [ 236.888462][ T7142] [ 236.890776][ T7142] read to 0xffff88812a995050 of 8 bytes by task 1062 on cpu 1: [ 236.898319][ T7142] watchdog+0x2c3/0x7c0 [ 236.902478][ T7142] kthread+0x1d4/0x200 [ 236.906542][ T7142] ret_from_fork+0x1f/0x30 [ 236.910927][ T7142] [ 236.913247][ T7142] write to 0xffff88812a995050 of 8 bytes by task 7142 on cpu 0: [ 236.920861][ T7142] handle_mm_fault+0x4a/0x530 [ 236.925519][ T7142] __do_page_fault+0x3fb/0x9e0 [ 236.930259][ T7142] do_page_fault+0x54/0x233 [ 236.934750][ T7142] page_fault+0x34/0x40 [ 236.938879][ T7142] [ 236.941183][ T7142] Reported by Kernel Concurrency Sanitizer on: [ 236.947327][ T7142] CPU: 0 PID: 7142 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 236.954766][ T7142] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 236.964801][ T7142] ================================================================== [ 236.972842][ T7142] Kernel panic - not syncing: panic_on_warn set ... [ 236.979411][ T7142] CPU: 0 PID: 7142 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 236.986850][ T7142] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 236.996882][ T7142] Call Trace: [ 237.000165][ T7142] dump_stack+0xf5/0x159 [ 237.004409][ T7142] panic+0x210/0x640 [ 237.008294][ T7142] ? vprintk_func+0x8d/0x140 [ 237.012875][ T7142] kcsan_report.cold+0xc/0x10 [ 237.017542][ T7142] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 237.023209][ T7142] __tsan_write8+0x32/0x40 [ 237.027699][ T7142] handle_mm_fault+0x4a/0x530 [ 237.032363][ T7142] __do_page_fault+0x3fb/0x9e0 [ 237.037112][ T7142] do_page_fault+0x54/0x233 [ 237.041598][ T7142] ? prepare_exit_to_usermode+0x154/0x1a0 [ 237.047300][ T7142] page_fault+0x34/0x40 [ 237.051436][ T7142] RIP: 0033:0x41d194 [ 237.055331][ T7142] Code: 48 83 c6 08 49 83 f8 08 0f 8d e7 00 00 00 48 39 de 0f 83 de 00 00 00 0f ba e2 00 0f 83 ca 00 00 00 4c 8b 4c 24 78 4e 8d 14 0e <4d> 8b 12 4d 85 d2 74 c9 4c 39 d0 77 c4 49 39 ca 73 bf 4c 89 44 24 [ 237.074927][ T7142] RSP: 002b:000000c4203c9e10 EFLAGS: 00010287 [ 237.080974][ T7142] RAX: 000000c420000000 RBX: 00000000000210d0 RCX: 000000c434280000 [ 237.088957][ T7142] RDX: 0000000000000009 RSI: 00000000000168d0 RDI: 00007f45cadbc000 [ 237.096912][ T7142] RBP: 000000c4203c9e78 R08: 0000000000000002 R09: 000000000186f740 [ 237.104862][ T7142] R10: 0000000001886010 R11: 000000c4203c9fc0 R12: 0000000000000008 [ 237.112814][ T7142] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 237.122112][ T7142] Kernel Offset: disabled [ 237.126428][ T7142] Rebooting in 86400 seconds..